302
FXUS65 KBYZ 310714
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
114 AM MDT FRI JUL 31 2026
KEY MESSAGES
- ISOLATED SHOWERS AND THUNDERSTORMS TODAY.
- VERY HOT & DRY SATURDAY WITH WIDESPREAD TRIPLE DIGIT HEAT; FIRE
WEATHER CONCERNS ELEVATED.
- WEAK FRONTAL PASSAGES EXPECTED BOTH SATURDAY NIGHT AND SUNDAY
NIGHT. MUCH COOLER MONDAY & TUESDAY.
- INCREASED SURFACE-BASED SMOKE MAY REDUCE AIR QUALITY LATTER HALF
OF WEEKEND INTO MONDAY.
DISCUSSION
THROUGH NEXT THURSDAY...
WEAK SHORTWAVE WILL BRING SCATTERED SHOWERS AND ISOLATED WEAK
T-STORMS FROM WEST TO EAST THIS MORNING. THIS IS ASSOCIATED WITH
AN ELEVATED LAYER OF MOISTURE AND MODEST INSTABILITY. SHOWERS WILL
REACH OUR EAST BY MIDDAY. FOR THIS AFTERNOON, ISOLATED CONVECTION
MAY DEVELOP NEAR SHERIDAN AND ACROSS SOUTHEAST MT, ESPECIALLY IF
A SURFACE TROF STALLS IN THIS AREA. ALL OF THIS ACTIVITY SHOULD
REMAIN WEAK, BUT HAVE ADDED LOW POPS TO COVER THE POTENTIAL.
UPSTREAM, THERE IS A TRAILING PV LOBE TRACKING FROM OR INTO
SOUTHERN ID. THIS ENERGY WILL HAVE A DRIER AIR MASS TO WORK WITH
AND BE COMPETING WITH RISING HEIGHTS TODAY, SO A LOW CHANCE OF
WEAK T-STORMS FURTHER WEST SHOULD BE CONFINED TO SOUTHERN
MOUNTAINS. LOOK FOR HIGH TEMPS IN THE 90S TO NEAR 100F TODAY.
SATURDAY WILL BE VERY HOT & DRY AS THE RIDGE AMPLIFIES AND A SURGE
OF HOTTER AIR ARRIVES FROM THE SOUTHWEST. 700MB TEMPS RISING TO
+16C TO +20C WILL PUSH TEMPS OVER 100F ACROSS THE AREA, SMOKE
PERMITTING. DAILY RECORDS ARE LIKELY, AND AUGUST RECORDS WILL BE
APPROACHED AT WESTERN STATIONS (SEE TABLE AT END OF DISCUSSION).
HEAT-RELATED HEALTH IMPACTS ARE A CONCERN AND AN EXTREME HEAT
WATCH REMAINS IN EFFECT. IN ADDITION TO THE HEAT WILL BE AFTERNOON
HUMIDITIES IN THE 7-12% RANGE. WE WON'T SEE A LOT OF WIND WITHIN
THE THERMAL TROF, BUT WESTERN AREAS SHOULD SEE MIXED SW WINDS
GUSTING OVER 20 MPH. A FIRE WEATHER WATCH REMAINS IN EFFECT FOR
WESTERN ZONES.
A WEAK COLD FRONTAL PASSAGE ARRIVES LATE SATURDAY NIGHT AND WILL
BRING 5-10 DEGREES OF COOLING FOR SUNDAY. POST-FRONTAL NW-N WINDS
WILL BE SOMEWHAT BREEZY IN AN AREA NORTH AND EAST OF FORSYTH, AND
THIS IS WHERE FIRE WX CONCERNS WILL BE GREATEST ON SUNDAY...THOUGH
ADMITTEDLY THE WESTERLY WINDS WILL BE MUCH STRONGER ACROSS
NORTHERN MT. RHS SUNDAY WILL STILL BOTTOM OUT IN THE TEENS, AFTER
A VERY POOR RECOVERY SATURDAY NIGHT.
ANOTHER FRONTAL PASSAGE ARRIVES SUNDAY NIGHT, BRINGING THE COOLEST
AIR MASS WE HAVE SEEN SINCE THE BEGINNING OF JULY. AS A SHARPER
UPPER TROF SKIRTS ACROSS NORTHERN MT WE MAY SEE BRIEF SHOWERS
ACROSS THE WEST AND NORTH SUNDAY NIGHT (TIED TO MID LEVEL
FRONTOGENESIS). MONDAY & TUESDAY LOOK DRY AND NOTABLY COOLER, WITH
HIGHS IN THE 70S TO LOWER 80S AND SEASONABLY COOL NIGHTTIME LOWS.
FINALLY.
ENSEMBLE CONSENSUS IS FOR RISING HEIGHTS AND A TRANSITION TO FLAT
RIDGING FOR THE MIDDLE OF NEXT WEEK. THIS WILL YIELD WARMING FOR
WEDNESDAY & THURSDAY WITH TEMPS LIKELY TO CLIMB BACK TO THE LOWER
90S. THE FLAT RIDGE WILL KEEP MONSOON MOISTURE WELL TO THE SOUTH,
SO THESE CONFIDENTLY WILL BE DRY DAYS.
SMOKE IMPACTS: POST-FRONTAL SUBSIDENCE AND SHIFT TO UPSLOPE WINDS
MAY YIELD HIGHER CONCENTRATIONS OF SURFACE-BASED SMOKE FOR THE
LATTER HALF OF THE WEEKEND INTO MONDAY. REDUCED AIR QUALITY IS
POSSIBLE. SOMETHING TO MONITOR OVER THE NEXT FEW DAYS.
BELOW IS A SUMMARY OF SATURDAY FORECAST HIGHS, WITH DAILY AND
AUGUST RECORDS, AT EACH OF OUR MAIN CLIMATE STATIONS.
SITE 8/1 FORECAST 8/1 RECORD AUG RECORD
BILLINGS 105 102 (2008) 105 (8/2/2024)
LIVINGSTON 104 101 (2000) 105 (8/5/1961)
MILES CITY 104 104 (2008) 110 (8/7/1995)
SHERIDAN 105 103 (2008) 106 (8/7/1983)
BAKER 102 99 (2022) 108 (8/12/2018)
JKL
AVIATION
06Z DISCUSSION...A DISTURBANCE CROSSING INTO THE WESTERN PORTION
OF THE FORECAST AREA AT 05Z WILL SLOWLY DRIFT EASTWARD OVERNIGHT
AND MOVE INTO SE MONTANA BY MID DAY, EXITING THE AREA BY EARLY
FRIDAY EVENING. THIS DISTURBANCE WILL BRING A CHANCE FOR MAINLY
LIGHT SHOWER ACTIVITY WITH ISOLATED THUNDERSTORM CHANCES EMBEDDED
MAINLY NEAR THE THE HIGHER TERRAIN AS IT SLOWLY CROSSES THE AREA.
DO NOT EXPECT SUB-VFR CONDITIONS WITH THIS ACTIVITY, BUT DO HAVE
PROB30 GROUPS FOR KLVM (06-08Z) AND KSHR (20-01Z) FOR
THUNDERSTORMS PRODUCING GUSTS TO 40KTS. OUTSIDE OF CONVECTION VFR
CONDITIONS AND LIGHT WINDS ARE FORECAST THROUGH THE DAY TODAY.
SOUTHERLY WINDS WILL INCREASE FRIDAY NIGHT OVER SE MONTANA AS THE
LOW LEVEL JET RE-DEVELOPS, WITH GUSTS TO 20KTS AT HIGHER EXPOSED
LOCATIONS, AND LLWS POSSIBLE ELSEWHERE. HRRR IS SHOWING NEAR
SURFACE SMOKE INCREASING OVER THE WESTERN FOOTHILLS BY EARLY THIS
EVENING. ADDED MENTION OF 6SM HAZE TO THE FORECAST FOR KLVM TO
COVER THIS BY 02Z. CHAMBERS
PRELIMINARY POINT TEMP/POPS
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 099 067/105 070/095 062/077 054/080 057/089 062/096
1/K 00/G 00/U 00/U 00/U 00/U 00/U
LVM 096 059/104 060/094 051/077 045/079 048/090 055/094
0/K 00/G 00/U 10/U 00/U 00/U 00/U
HDN 099 063/106 068/096 059/079 050/082 054/092 059/097
2/T 00/G 00/U 00/U 00/U 00/U 00/U
MLS 099 066/104 074/094 063/079 051/080 056/090 062/097
2/T 00/G 00/U 00/U 10/U 00/U 11/U
4BQ 095 065/101 073/095 065/081 055/081 059/090 064/096
2/T 00/G 00/U 10/U 00/U 11/U 11/U
BHK 094 063/102 068/096 061/081 049/078 053/088 058/095
2/T 10/G 00/U 10/N 00/U 01/U 11/U
SHR 095 059/105 064/098 059/081 049/082 052/090 057/096
2/T 00/G 00/U 00/U 00/U 11/U 00/U
BYZ WATCHES/WARNINGS/ADVISORIES
MT...EXTREME HEAT WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SATURDAY EVENING FOR ZONES
29>34-36-37-40-42-56>58-63>66-138-139-141-169-170-172-173-228-235.
FIRE WEATHER WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SUNDAY EVENING FOR ZONES 117-123>128.
WY...EXTREME HEAT WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SATURDAY EVENING FOR ZONE 199.
WEATHER.GOV/BILLINGS
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